There are a number of prior art methods and apparatuses which are used in the detection and treatment of cancer. Fluorescent markers have been used to help identify cancerous tissue within a patient. There are also a number of prior art methods and apparatuses which relate to flow cytometry and the act of segregating and counting malignant cells within a tissue sample. One example of a prior art reference which discloses the use of fluorescence detection for cancer screening is U.S. Pat. No. 5,270,171 to Cercek, et al. This reference teaches a method to identify, separate and purify the factor or factors that provoke a response by SCM (structuredness of the cytoplasmic matrix) responding lymphocytes. The use of such purified factor or factors enhances a SCM cancer screening test. The SCM is a peptide of at least nine amino acid residues. The residues produce at least a 10% decrease in the intracellular fluorescence polarization value of SCM responding lymphocytes from donors afflicted with cancer. Antibodies specific for the SCM factor are useful in immunoassays that can detect the factor, including detection of cancer cells grown in vitro. The SCM factor is useful for screening of blood samples and other body fluids or cell aspirates for the presence of malignancy in the donor. A method is also disclosed for testing lymphocytes obtained from the donor for presence or absence of a malignancy. A further method is also disclosed for screening a blood sample for the presence of a malignancy in a body of a donor.
U.S. Pat. No. 5,554,505 to Hajek, et al. discloses an optical screening method and apparatus for identifying both the morphology and selective characteristics or properties expressed by cells, such as cancer cells. Cell samples are combined with one or more sets of microspheres, each set having a reactant bonded thereto which will bind the microspheres to a specific molecule which can exist on one or more types of cancer cells. The cells and microspheres are formed as a smear on a slide, stained with a histological type stain and optically viewed to identify the type of cells to which the different set of microspheres do or do not bind. A quick cancer screening method is provided by adding selected sets of microspheres comprised of unique reactants to different sample smears of cells, and optically screening the sample smears for interaction with the microspheres.
U.S. Pat. No. 5,562,114 to Chu, et al. discloses a diagnostic immunoassay method using monoclonal antibodies. These monoclonal antibodies are capable of identifying an antigen associated with carcinomas of ductal lineage and can be used both diagnostically and therapeutically. More specifically, the monoclonal antibodies of this reference are capable of targeting the breast carcinoma cells in vivo. The monoclonal antibodies are purified and are labeled with radioactive compounds, for example, radioactive iodine, and then are administered to a patient intravenously. After a localization of the antibodies at the tumor site, they can be detected by emission, tomographical and radionuclear scanning techniques thereby pinpointing the location of the cancer.
U.S. Pat. No. 5,087,636 to Jamieson, et al. discloses a method to identify and destroy malignant cells in mononuclear cell populations. This method includes the steps of contacting a composition of bone marrow cells or other cells with a green porphyrin of a specific compound, irradiating the cell composition with light at a wave length effective to excite fluorescence of the green porphyrin, and then detecting the presence or absence of fluorescence indicating malignancy. This reference also discloses the steps by which the bone marrow cells are removed, separated, washed and diluted to an appropriate concentration for treatment, incubated, centrifuged, and exposed to the irradiating light.
U.S. Pat. Nos. 5,308,608 and 5,149,708 to Dolphin, et al. disclose specific types of porphyrin compounds which may be used for detection, photosensitization, or the destruction of a targeted biological material when the targeted tissue is contacted with the specified porphyrin, and irradiated with light that excites the compound.
U.S. Pat. No. 5,211,938 to Kennedy, et al. discloses a method of detection of malignant and non-malignant lesions by photochemotherapy of protoporphyrin IX precursors. 5-amino levulinic acid (5-ALA) is administered to the patient in an amount sufficient to induce synthesis of protoporphyrin IX in the lesions, followed by exposure of the treated lesion to a photoactivating light in the range of 350-640 nanometers. Naturally occurring protoporphyrin IX is activatable by light which is in the incident red light range (600-700 nanometers) which more easily passes through human tissue as compared to light of other wave lengths which must be used with other types of porphyrins. In short, the use of 5-ALA makes cell fluorescence easier to observe, and also greatly reduces the danger of accidental phototoxic skin reactions in the days following treatment since protoporphyrin IX precursors have a much shorter half life in normal tissues than other popularly used porphyrins.
Another set of references exists which relate to flow cytometry utilizing fluorescence producing compounds. One such prior art reference includes U.S. Pat. No. 5,605,805 to Verwer, et al., which discloses a method for determining the lineage of acute leukemia cells in the sample by fluorocytometry. Other examples of fluorocytometry utilizing fluorescence include U.S. Pat. Nos. 5,418,169 to Crissman, et al., U.S. Pat. No. 5,556,764 to Sizto, et al., and U.S. Pat. No. 5,627,040 to Bierre.
Present methods relating to cancer screening using fluorescence detection systems require the use of interventional devices such as endoscopes which have the special capability of delivering specified light frequencies to a targeted area within a patient. These endoscopes illuminate the targeted part of the body in which cancer is suspected. The light delivered at a specified frequency illuminates an area which has previously been subjected to some type of fluorescent marker, such as a porphyrin which causes malignant cells to illuminate or fluoresce under observation of light at a specified frequency. In all cases, introduction of an endoscope into the body requires some type of sedation or general or local anesthesia. Once a tumor has been located by use of the interventional device, depending upon the type of tumor, photochemotherapy or other treatment means can be used. However, prior to actual treatment, there must be a confirmed test of cancer. Accordingly, the tumor still needs to be sampled by an appropriate biopsy method. Generally, biopsy methods also require some type of sedation or anesthesia. Thus, traditional methods of confirming a malignancy may require at least two interventional surgical procedures.
While each of the foregoing references may be adequate for their intended purposes, many of these inventions require surgical techniques to remove the cell samples which can be traumatic to the patient. Furthermore, many of the references require complex equipment, and special medical expertise in order to conduct the procedures and to make the diagnoses. Therefore, there is a need for a reliable cancer screening technique or method which can test for cancer in a wide variety of cells and which may be accomplished by non-invasive or minimally invasive cell collection techniques which limit patient trauma, are inexpensive to conduct, and can be confirmed positively by a pathologist, oncologist or other physician without additional testing or screening. The invention described below provides each of these advantages, among others, which will be apparent to those skilled in the art.